This is exactly what I needed right now. To hell with politics and culture wars, i'm going to the moon.

One problem I always have watching SFIA videos. Sometimes the graphics or animations on screen are so cool that I'll be watching and thinking about those, then suddenly I realize I've missed the last 1-2 minutes of what Isaac is saying.

Once again, with all the discord and anger in the world, it's so refreshing to hear a positive outlook for the future.

This subject is near and dear to my heart, to the point I'm going to write an essay-length comment about it! I finished my aerospace PhD in 2017, but I'd been shoehorned into a dissertation topic that was basically Applied Math without any real engineering involved. As soon as my work was done, I set out on a six-month (solo, unfunded, hobbyist) research project to get a taste of what I'd been missing. At first I was inspired by Neal Stephenson's novel _Seveneves_ and wanted to give it the Andy Weir treatment, rewriting it with the most accurate science and engineering I could manage, but I wound up not writing any fiction -- I just brainstormed the technology. Half my time went into ISRU for moon rocks. I haven't touched the subject since 2018, so I'm thrilled to learn about Blue Alchemist ... even if they just made half of my ideas obsolete. (lol!) I think of lunar rock as similar to particle board "wood" made of glued-together sawdust, only instead of glue it has oxygen, and instead of sawdust it has a potpourri of a half-dozen metals. At least back when I looked at it, it seemed the biggest difficulty wasn't removing the oxygen; it was separating the different metallic elements from each other. The papers on FCC Cambridge I could find at the time just yielded (1) oxygen and (2) a garbage alloy of all those metals mixed together. I'm willing to bet that if a human hit an ingot of that alloy with a hammer, it wouldn't dent -- it would crack, or even shatter. It sounds like someone has found a plausible way to address that since. (Either that or my initial lit search wasn't thorough enough!) And Blue Alchemist, with a working prototype, is just bananas. The non-metals part of my research did give me a couple neat ideas, though. One is the use of basalt fiber -- literally just melted basalt, extruded the same way you extrude fiber optic quartz. It has roughly the same strength as fiberglass (without the epoxy matrix, which uses elements that are rare on the moon), and could be used for tethers or industrial fabrics. However, people are working on using aluminum in place of epoxy as a matrix for basalt fibers, which would allow you to manufacture a true composite material using only lunar resources. Such a thing might allow creation of composite-overwrapped pressure vessels (COPVs) with imperfect alloys for the inner tank. But really, the thing I was most excited about (which is now half obsolete) was a process proposed by Donald Burt in 1992 and refined by Geoffrey Landis in 2007. It brings potassium fluoride (KF) to the moon and recycles both elements in a closed cycle. I realized it probably also needs hydrogen at a couple points, but that too would be recyclable, and might be extracted from polar ice if it isn't brought from Earth. It begins be using electrolysis to separate the fluorine, which is piped at 500 Celsius into a reactor vessel filled with lunar dust or pulverized rock. (Note that this is _absolutely insane_ -- IMHO, "Fluorine at 500 C" is the Maximum Kerbal approach to ISRU, which is what made it so fun to research.) The fluorine both displaces oxygen in the mineral crystal lattice and combines with silicon to form SiF4, which is a gas at that temperature. The removal of structural oxygen and silicon and the creation of excess gas inside the crystal causes it to shatter, exposing more of it to the fluorine until it's all been transformed. The output of the reactor vessel is then SiF4, oxygen, residual fluorine (the three of which can be separated by cryogenic distillation) and a mixture of fluoride salts -- mostly FeF3, AlF3, CaF2 and MgF2. I added a step here to use a combination of water, hydrofluoric acid (HF) and sulfuric acid (using lunar-sourced sulfur) to fractionally dissolve the salts and separate them. Then, the application of molten potassium to the first two salts yields pure iron, pure aluminum, and pure KF; applying potassium oxide to the other two yields pure lime, pure magnesia, and more KF. Meanwhile the SiF4 could also be reduced by potassium, but if you need ultra-pure silicon for solar panels or computer chips, you would need to incrementally break it down with hydrogen and very high temperatures: SiF4 -> SiF3H -> SiF2H2 -> SiFH3 -> SiH4 -> SiH3 -> SiH2 -> SiH -> Si. At the end you have a tank of oxygen, a pile of lime, another pile of magnesia, and one ingot each of silicon, iron, and aluminum ... and a pile of KF, which goes back into the electrolysis cell to start the whole process over again. If you have some hydrogen to spare, a fun possible side product is the silane (SiH4). Because it's fair to guess that even polar water ice will be very difficult to collect in large quantities (I mean, it's probably in the form of a light frost mixed with 10000 times as much dust), that hydrogen will be precious -- if you burn it for rocket fuel, you want to get as much out of it as you can. Well, if you measure your rocket efficiency in terms of "delta-V per kilogram of hydrogen burned", it turns out silane is _far_ more efficient than pure hydrogen. The only downside is the fact that the combustion product is SiO2, and fun fact, rocket turbopumps are ... uh ... _notoriously sensitive_ to the presence of molten quartz in the turbine. Luckily, electrically-pumped rocket engines became a real thing in 2018, so we could just burn the silane in a combustion chamber without any turbine. After that, we just need to design a chamber+nozzle shape that ejects the quartz without accreting it or clogging. (Thanks for coming to my TED talk.)

Since I have been watching SFIA I have had a much more positive outlook on the future and in life in general. Being excited about the future has made me a happier person. Thank u Issac, keep up the good work. 👍

I'm a simple man. I see a new Isaac Arthur video, I watch it, and my day is made. 😊

I’m over the moon for this; she may be a harsh mistress, but who isn’t a lunatic at times?

There we go, another Arthursday with snacks and drinks

New season: *arrives Isaac Arthur: Moon time

One thing I really liked in the book Artemis was that the life support system was fed from a giant Aluminum smelter nearby the main city. :)

People seem to think that all you need to conquer space is Rocket + 3D Printer + Hype. But this is the real meat a potatoes. It drove me up the wall for years and years that no one was going deep into in-situ resource refining. This is a sign we're finally putting on the big boy pants.

You are 100% correct. The moon ought to be our first outpost, and we should postpone venturing to Mars with people until we gain a lot of confidence on the moon, and have ways of earning profits from our space ambition.

Let’s go! Been waiting for more on this topic since your upward bound series! Keep up the great work SFIA!

I've been following a bunch of the ISRU test robots for lunar work builders on Twitter, seeing those machines come together piece by piece and CLPS missions get announced just keeps building the excitement.

This is one of the better episodes. I like equations and numbers more than broad generalizations.

Happy Arthursday early gang🎉🎉🎉

Yes!! Thank you, Isaac, for reading comments and taking video topics from your viewers!! It's so amazing seeing your idea come to life! This episode was exactly what I wanted to learn about. I would love a part 2!! Thank you again!

This is a great episode. When you compare the energy cost of a mass driver to electrolysis for getting off the Moon, that's the content I like!

Radiation is a major roadblock. It comes in two major types (1) galactic cosmic rays, and (2) solar storms. Your best shields are (1) lunar regolith, and (2) your supplies. Using regolith as the measuring stick: (1) anything less than two meters thick only turns cosmic rays into shotgun blasts of lower energy radiation, and (2) you need four to five meters to match the projection of Earth's atmosphere. Expect 0 to 5 solar storms a year with a few hours' notice. Thise would be fatal to anyone on the surface.

the moon is the first checkpoint in our perpetual expansion of the universe

I’m in hospital now waiting to get my antibiotic resistant tonsilitis ridden tonsils removed that went to Grade 3/4 in a single night, this exactly what I needed right now to distract me from everything. I promise I watch for more positive reasons most of the time!❤❤❤

Apollo 11 launched on my 5th birthday. This month I will be 59 so 55 years since that first landing. I fully expect SpaceX to do much better in the settlement of the moon than NASA or any other government organization.

love your stuff keep them coming with the great quality you give every time !

In times like these, it is always good to hear and see optimistic visions of the future, especially as an aerospace engineering student at LTU grasping for any hope that I'll end up building orbiters rather than missiles.

Your talks about the future of space travel are always of interest to those of us that grew up on a steady diet of science fiction - for us older folks, seeing many of those sci fi stories come true is both fascinating and scary - one hopes more of the best case scenarios come true than the worst! Only by avoiding wars and other destructive forms of competition will we be able to move into these shiny dreams... here's hoping and praying we can do so... Metallysis, wow.... that's a high energy process! I dunno if the terajoules needed will be available... maybe if fusion power is standard, or we come up with a new catalytic process....

It is so good to hear about near-term strategies for getting lunar materials for lunar use, earth orbit, and for enabling lower cost options for mars, asteroids, and satellites of the outer planets. Thanks Isaac!

There's a minecraft modpack where the basic premise is just this, mine, process, refine and build the infrastructure needed to produce an interstellar spacecraft. I forget the name of it. But it even had Ilminite as a mineral you could find, and the means to mine the asteroid belt. The primary means to process all these was a mod called "Minechem" and if I had to imagine futuristic shenanigans turning one element on the periodic table into another, and seperating them out from other objects already in your vicinity, this is what I imagine. Minechem is a good mod for memorizing compounds and atoms. And I wouldn't mind if you checked it out and commented on how good or poor it is in terms of accuracy. Obviously with minecraft there is always going to be a certain amount of fantasy. But the chemistry aspects I would be curious to hear an "expert's" opinion about.

IA: If we can use charged 'tethers' in lunar orbit to attract charged sub micron regolith dust that 'fountains' up at the terminator, then we can start building in orbit. Rotating habitats are better for humans IMO. I don't think we're ready to go up and down the lunar gravity well just yet. I think we need to build platforms at L1 through L5 first.

The moon episodes are my favorite. More please!

Nice animations for your article on the feasibilities of the Moon as a launch pad for further Solar System explorations. Thank you for this presentation. I hear and read so much about asteroids as source materials that it's good to be reminded that we need to start from somewhere close to Earth. Cheers and out😊

While I have enjoyed the couple of shorts you have done. I much prefer your long-form content. I enjoy the lengthy explanations you give. I have liked every episode you have put out.

The shorts are working. I saw the one about Birch Planets and so I watched the Mega Earths episode and then put on a mix to fall asleep to. I've been subscribed for years and I still saw the short and went to watch the full episode again so they are working.

Good job Isaac thank you for your videos.

Oh thank you so much for this espoide, Im writing a book about the need to get more info on this. 🖖

One power source I think might be overlooked; air; first you run a large pipe, ten feet or more in diameter. Along it's length you place wind turbines. With bypass pipes for maintenance. Have it run from light areas to the dark, along the solar pathway across the Moon: it could run continuously because the heated air flows to the lower pressure area, if the tube circumnavigates the Moon, a continuous wind would result

"To the moon, Alice, to the moon!” - Ralph Kramden, Space pioneer and visionary

Isaac you are a blessing!

"Oxygen is Heavy." Duuuuuuude ........ That's like so totally deep .......

Yes! Arthursday again!

Spacesuits. The Apollo spacesuits were wrecked in three days. The entrance of any human habitat must start with a large suiting/unsuiting room. It will need major equipment to control the dust particles. These particles have never rolled in flowing water, so they are not rounded off. They are major abrasives and subject to electrostatic attraction. They are a danger to all mechanical equipment.

Video got uploaded the same day I finished Artemis by Andy Weir. Perfect timing Isaac!

Perfect again and thank you for your priceless time and effort my friend's to you both 💯🍻✌️

Basalt fiber composit has 3 times the strength of steel and one third of its weight. So it is ideal for lightweight rugged strucuteres such as pressure vessels needed for rotating habitats, tethers and beams. Basalt is truely abundant on the moon an " only" needs to be melted at about 1500°C to be spun out to the very fine fibers needed for the composit. The other component- resin- is needed at a fraction of its weight, reducing transportation expenses considerably. And more importantly all size restrictions from rocket fairings become meaningless!

I love your videos! Great work once again!

Aluminum can be used for wiring instead of copper. It's done all the time. Not as easy to work with as copper, and you have to take some precautions, but it can be done. I hope I live long enough to at least see a lunar settlement.

lunar space elevator can be built with existing technology - we don't need carbon nano-tubes to build it. Why not build one from L1 to Lunar Pole? L1 is easier to get to than Lunar orbit, and a station at L1 is a stable place to build. A station anchored at L1 wouldn't be rotating in orbit around the moon, so stresses on the elevator ribbon are reduced. The Lunar Pole has constant sunlight, while the rest of the moon has 14 consecutive days of darkness every 4 weeks, so solar energy is always available. The elevator can bring processed fuel & oxygen up to L1 for spaceships traveling back and forth to LEO. The poles are ideal for solar power and ice/mineral collection and conversion.

Awesome!

This episode is phenomenal. I'm sending this to everyone who asks me why I like space. It explains why I think going to space will help protect the earth from us, not just to burn through the earth and hope we can live elsewhere in time. The future is good! But we need to be optimistic and focused and angry about the present to keep it that way!!!

Big for utilizing near earth orbit and the mood might be from the "Two bit Da Vinci" article "Pumping Water Without Blades - Magnetic Pumps - Future of Propulsion?". This tech might make everything spoken about here much more efficient.

We discuss sending missions to near earth asteroids to get precious metals, but we should remember that it might only be necessary to have settlers or their robots prospect the many lunar craters for the remains of previous asteroid impacts they may strike it rich!

13:26 In general, the government paying out money to anyone who can achieve specific goals could be a great way to colonize the moon without a specific government program for it. And it would probably be 10x more efficient. Like X dollars per person on the moon per day, X dollars for a spectroscopy of that rock, X dollars per kg of iron, etc.

Everyone keeps looking at Mars but ignores all the advantages of setting up infrastructure and gaining experience on the Moon. I am glad Isaac devotes such great attention to our big grey satellite. Another good episode Isaac.

I wounder if there is a way of implementing cold welding as a means engineering in space like a 3D printer but using space itself for the welding part

Isn't lunar dust charged? I was under the impression that was why it stuck so tenaciously to Apollo spacesuits and why it can wreak such havoc with electronics and bearings. It gets in any cracks and is insanely abrasive. The positive side to this is a cathode should act like a vacuum while an anode should act like a leaf blower.

yeah, just looking at that low-gravity garden visualization and thinking of other stuff with pumps motors etc, bearings and bushings will be one of them things that will need to be mass produced given how prolific lunar dust clings to everything. I'm not even sure if traditional forging or 3D printing would be preferred for such things, given how fast something can be printed before it burns/boils away from the heat as pointed out in the molecular 3d printing episode (The Santa Claus Machine).

I just hope it doesn't turn out like the premise of the 2012 film, "Moon" - which, btw, is one of my favorite movies and I would recomment to any sci fan fan, even if it is depressing.

Great episode!❤

I'd like to see a video focused in on the most cost effective way of supplying electric power for Mars. My current favorite is low-Mars-orbit solar power satellites (about 90 minute orbital period) that charge up batteries from solar panels, then transmit it down to an antenna array on the surface while passing overhead, where excess power is again stored in batteries. Downsides: Moderately large losses going into and out of batteries, and the low orbit means you don't get nearly as constant solar irradiation as a traditional SPS. Upsides: - Much less mass delivered to the surface (e.g. about 1/8th the battery mass needed for constant night time power) - Still takes care of the day-night cycle issue of ground based solar (passing over the ground antennas around 16 times daily with a ~500km orbit) - Keeps the space and surface antenna arrays far smaller than a traditional aero-synchronous SPS would (a huge advantage for an early Mars base) - Microwave transmission will basically ignore dust storms making the energy supply far more reliable than ground based solar.

You got me messed up. I was looking up what resources were abundant on the moon last night

Look at Moon Industry based in The Netherlands. They are part of the Artemis, with the Break the Ice Lunar Challange and work on these things.

A video on lunar dust and approaches for dealing with it could be cool. Yeah, it sounds a little topic and/or boring, but it really seems to be the main engineering challenge and maybe even a show-stopping problem for mid and longer term development. The fact that the Apollo Lunar Excursion suits had lifespans in the dozens of HOURS because of the effects of the dust is pretty sobering.

ROCK AND STONE!

10:42 - an 80-person team would need 70 kg of O2 per day or ten minutes of metalolysis for a 10,000 kg per day system. One minute would be for an 8-person team.

As an autistic school teacher and parent with four kids under age 11, these videos have been a legitimate lifeline over the past few years and have very much inspired a lot of my writing. My personal goal is to finish a manuscript and even if it never gets published, send you a copy to see if you catch all the references to SFIA-isms ;)

The moon is the most amazing place

What about nitrogen for plant growth, as an inert gas for breathing, for chemicals? Are there reasonable amounts of (extractable) N on the lunar surface or will it all have to be "trucked up" from Earth?

This is probably a pointless question, but how much mass could we have to mine and remove from the moon before it impacted the moon's tidal effects on the Earth (and hence oceanic ecosystems)? In contrast, how much mass would we be bringing to the moon to perform and maintain these activities. This is probably one of those order of magnitude circumstances where this question doesn't matter, but I thought I would ask any way.

@Isaac Arthur I have a question regarding 3D printing, considering the method things are produced via 3D printing being layers printed on layer, how much weaker would it be compared to a single cast mold? or is it a case that its design would make it stronger up to a certain point due to it possessing a smaller core to snap, but its not like there are any gravitational forces keeping each piece together either so its essentially the strength of the glue keeping the parts together. Now I'm not sure but I would assume the impact would be less considering there would be less stress being applied to the materials in space but yea. (apologies for the lack of correct terminology, I haven't had any formal training)

If you smelt ore for two weeks, the hot Metal might provide energy for the other two.

Didn't the prize for 5kg/8h already expire? Can't find anything up to date online, at least

Typical farming on the Luna would be to risky, best to tunnel into the surface about 10 meters down and use artificial lighting.

I was watching this again. And thought why not one of those spin launch thingies that they’re working on in Arizona? Seems a much less work and resources or in other words a more compact system for launching stuff off the moon.

You forget to mention the abrasive and static cling of the moons surface and how it acts like quick sand. The moon is like the worst place to go tbh

Wanted to suggest a topic for your video… Is it possible to make the orbit of the Earth (or a similar planet) have many satellites, and not one, the size of the Moon? or can there be many Earth-like planets in one orbit (for example, Earth's orbit)? And is it possible that there are examples found in space?

Thoughts on the spin launcher?

24:47 i love JP Aerospace, but mate, that is an inflatable STRATELITE hovering in the background of a MOON scene. N o. That mishmash scene makes as much sense as someone running around on fire while underwater.

I'm traveling for work right now, in a different city and timezone, all very unfamiliar and alienating. But your videos are like a warm blanket. :)

This and asteroid mining has been one of my favorite topics for almost a decade now. I wonder if there is any good type of social science research I can do on this topic for a doctoral dissertation?

would mining asteroids make more sense, than mining the Moon? Less deltaV to overcome.

Oh dang. o7 Good evening, Mr. President.

Kerns. For has long has humans have moved around, they have marked the way with stacks of rocks called kerns. Plent of rocks available on the Moon for free. Your graphics should show all pathways marked with kerns. Some a meter tall; some five. Kerns and mole hills will define the visual style of the settlement.

15:00 - I believe the solar wind can also cause a charge to build up on lunar dust, causing a sort of atmosphere of dust over the surface of the moon.

I have a recurring dream in which humans have gotten past the hate for each other and started working on becoming a Kardashev type 1 civilization. I hope we can make it.

It is interesting to point out that spinlaunch's current suborbital launch platform, if placed on the moon, could launch with a velocity very near the lunar gravity escape velocity. A spinlaunch platform on the moon will help Cheaply and rapidly launching materials to quickly build out space infrastructure around earth and the moon. Infrastructure like space based solar power and counterweight mass for solar powered tethered momentum transfer stations to get to Mars and back quickly, as well as provide reactionary mass for planetary defence from asteroids.

I think most if not all intergalactic space ships would have a fully functional VR town consist of those on the ship and AI NPC's, in this VR, you would be able to go to school/collage to learn stuff, maybe they spend most of their time in this VR working different jobs, making credits which could be used to purchase a home or apartment and anything you would want like a fully functional TV, radio, and a computer, a person could go on their computer in the VR to take control over a robot on the ship to take care of anything that needs attention in the real world, They could even date another person on the ship or a VR AI and could even have kids which the AI on the ship would combine their DNA together and grow this new person in a breader area of the ship, they might have to log out of the VR to exercise their real world bodies, I could go on but it would be awesome to produce an episode about VR simular to real life on these ships, This is why I don't think people will get board on these centuries voyages, kind of like being in a stasis on the ship but living out a normal life in VR

Isaac, I thought that the Solar flux density at the earth / Moon distance from the sub was around 1,000 watts/m^2, not 100 w/m^2 like you said twice in this video. Did I miss something somewhere?

I've often wondered why static electricity collection stations aren't viable at the poles and in larger craters. It seems there's an obscenely large and endless amount of electricity in those locations which we could capture and use with very little expense.

How would the strength of steel or other metals be different manufactured in the moon versus the same thing manufactured on earth?

Space/moon bases would not waist energy with flashing lights unless it was necessary for a landing pad at the time a ship was landing. For solar power the moon base would need to be built on the shadow/light line . That way the panels would only need to rotate for the 2 week light cycle.

4:32 cool! They turned Bobba Fett’s head into a power plant!

What are your thoughts on laser propulsion? I personally think if it was combined with solar or nuclear power technology it could be done with minimal environmental impact. Blast a block of frozen propellant with laser, make rocket go zoom

Digging and extraction of moon is safe I promise

im suprised how little lunar gem stones get in attention just the idea of lunar emerald is enticing

Our first step should be on the moon. Lunar base, launch pad, orbiting refueling station, etc. After this is when Mars should be on our horizon. Rinse and repeat lunar plan on Mars, all the while expanding to father reaches of space like the asteroid belt. That's about 250-300 yrs of development.

Subbed 👍🏾

I would think a fusion reactor would be more desirable than a fusion reactor anywhere.

Lets do it.

@i % your doing just fine. It's thanks for keeping the plands of your on your courses! So just don't care for Bic!

Did the spirits from outer earth qullfide for nap soon? It's about the difference of lands #

I wonder how one would be able to create hydrocarbon based components on the moon- manufacturing plastics would be…. Comically difficult.